Accordingly, it seems to me that there is something wrong with most dumbbell distinctions: those divisions appear to be so simple and clear that they seem to be all that you need—and that satisfaction tempts you to stop. Yet most of the novel ideas in this book came from finding that two parts are rarely enough—and eventually my rule became: when thinking about psychology, one never should start with less than three hypotheses!
Why do people find it so hard to classify things into more than two kinds? Could this be because our languages don’t come with verbs for speaking about trividing things? We all are good at ‘comparing’ pairs of things, and making lists of their differences—but few of us ever develop good ways to talk or to think about trifferences—that is, about relationships among triplets of things. Could this be because our brains don’t come equipped with adequate, built-in techniques for this?
...we'll need to being with some way or ways to divide an entire mind into parts–-and our everyday folk-psychology abounds with ideas about dividing the fhucntions of minds into pairs like these:
Conscious vs. Unconscious
Premeditated vs. Impulsive
Deliberate vs. Spontaneous
Intentional vs. Involuntary
Cognitive vs. Subcognitive